Hydrocarbons and other desirable fluids are located below the earth's surface and/or below the seafloor. To gain access to the hydrocarbons a well is drilled into the earth. The well is normally cased with a metal casing that is secured in place by cement. To produce the hydrocarbons it is often advantageous to perforate portions of the casing to allow hydrocarbons and other reservoir fluids to flow from the formation through the perforations and into the casing. Once the hydrocarbons are inside the casing they can be produced to the surface.
The perforations are commonly created using shaped charges. Shaped charges have a case, explosive material, and an inverted conical liner. The internal shaped charge geometry is arranged such that when the explosive initiates, the case confines the detonation, and the inverted conical liner collapses to produce a high-pressure jet of liner material. When a shaped charge is used in an oil well, the jet that is produced penetrates the casing, cement, and reservoir rock.
Shaped charges are generally delivered into an oil well using a perforating gun, which is a specially designed longitudinally extending tubular device. Shaped charges are commonly arranged in a perforating gun such that each charge is located in close proximity to a detonating cord. The detonating cord extends along the perforating gun and may be initiated in a variety of ways depending on the situation.
The present application relates to and describes a design for advantageously initiating the detonation cord by utilizing a miniature shaped charge.